Despite the gloriously colourful screens used in devices like the new iPhone 7, monochromatic E Ink displays have remained a popular choice for devices like e-readers since they're cheap, durable and work fine in direct sunlight. It also means they're the perfect technology for turning trucks into in-your-face rolling billboards.
The giant E Ink displays, developed by Mercedes-Benz, Visonect and RoadAds Interactive, are actually each made up of four 32-inch E Ink screens that are synced to function as a single 1m-by-1.5m display with a resolution of 1440 x 2560 pixels and 16-levels of grayscale.
Powered only by electricity drawn from the truck's battery, the E Ink displays are easy to mount and remove, so they can be transferred from truck to truck depending on its route and schedule. And they're durable enough to withstand dust, inclement weather and even a trip through a car wash — if you could find one large enough for a semi-trailer.
The E Ink displays also feature built-in 4G functionality, Wi-Fi and GPS, allowing the advertisements displayed to be constantly updated, but also relevant to where the truck happens to be rolling through. That's part of the reason trucks aren't already slathered in ads; the next day the vehicle could be three states away and billboards tend to be highly localised.
In terms of advertising, the truck on the road right next to you is going to make a stronger impression than a billboard on the side of the road that whizzes right past you, so there's certainly some great potential for exposure with this approach. But the E Ink screens could also be used to supply information to other motorists, such as impending slow downs ahead, or other emergency details. They could even provide more accurate and up-to-date 'how's my driving?' information for shipping companies to keep tabs on their employees — much to the chagrin of the driver behind the wheel.